PSL: MR_PLOTTER DISK_USAGE Added dummy json file for when cron not running.
PSL: MR_PLOTTER DISK_USAGE Added dummy json file for when cron not running.

Signed-off-by: Peter <4b8373d016f277527198385ba72fda0feb5da015@powerstandards.com>

PingThingsIO/pt-mr-plotter,PingThingsIO/pt-mr-plotter,PingThingsIO/pt-mr-plotter,PingThingsIO/pt-mr-plotter,PingThingsIO/pt-mr-plotter,PingThingsIO/pt-mr-plotter,PingThingsIO/pt-mr-plotter